fix(gateway): make sgl-model-gateway a cargo workspace so maturin 1.14 accepts the parent README

[JustinTong0323]

Motivation

The dev docker image build recently started failing on both build-x86 and build-arm64:

💥 maturin failed
  Caused by: `project.readme` path `../../README.md` resolves outside
             allowed metadata root `/build/sgl-model-gateway/bindings/python`

Root cause: maturin 1.14.0 added PyO3/maturin#3182 "Support parent-relative pyproject metadata in sdists", which bounds a parent-relative project.readme to the cargo workspace root (see project_layout.rs: allowed_metadata_root = if pyproject_dir.starts_with(workspace_root) { workspace_root } else { pyproject_dir }). The Dockerfiles install maturin unpinned, so they picked up 1.14.0.

sgl-model-gateway has no [workspace] — the root crate and bindings/python are independent packages — so cargo metadata reports each crate's own directory as its workspace root. bindings/python/pyproject.toml then has readme = "../../README.md", which resolves to sgl-model-gateway/README.md, outside bindings/python/, and maturin rejects it.

Because that pyproject.toml is shared by every maturin build path, this is not limited to the dev image — it also affects docker/gateway.Dockerfile, docker/rocm.Dockerfile, .github/workflows/pr-test-rust.yml, the PyPI release, and sgl-model-gateway/Makefile.

Modification

Declare sgl-model-gateway as the cargo workspace root with bindings/python as a member (the golang bindings and wasm examples stay standalone via exclude):

[workspace]
members = ["bindings/python"]
exclude = ["bindings/golang", "examples"]

Now cargo metadata from bindings/python reports sgl-model-gateway/ as the workspace root, which contains README.md, so the existing readme = "../../README.md" resolves inside the allowed metadata root. This is exactly the layout maturin #3182 is designed for.

• No change to which README ships on PyPI — the readme field is untouched, still the repo-root gateway README.
• Version-agnostic — fixes every maturin build path in one place rather than pinning maturin in 6+ scripts.
• Build profiles (release/ci/dev) already exist at the workspace root, so the now-redundant [profile.ci] in bindings/python/Cargo.toml (byte-identical to the root one) is dropped — cargo ignores profile tables in workspace members anyway.

Why the lib.rs formatting changes?

bindings/python was previously its own standalone crate, so the rustfmt sgl-model-gateway pre-commit hook (cd sgl-model-gateway && cargo +nightly fmt -- --check) never reached bindings/python/src/lib.rs. Making it a workspace member brings it under the gateway's rustfmt.toml (group_imports = "StdExternalCrate", imports_granularity = "Crate") for the first time, which is what the Lint job flagged. The lib.rs change is purely that one-time cargo +nightly fmt normalization (import grouping + chain/struct wrapping) — no logic change.

Checklist

• Format your code according to the Code Formatting with Pre-Commit.
• [profile.ci] (used by pr-test-rust.yml --profile ci) is preserved at the workspace root, identical to the dropped member copy.

Testing: https://github.com/sgl-project/sglang/actions/runs/27394688617/job/80959410404

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CI States

Latest PR Test (Base): ✅ Run #27395362207
Latest PR Test (Extra): ❌ Run #27395362141

[gemini-code-assist]

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[JustinTong0323]

/tag-run-ci-label

[JustinTong0323]

/tag-and-rerun-ci

[JustinTong0323]

Very strange issue...

[dougyster]

https://github.com/sgl-project/sglang/actions/runs/27394688617/job/80959410404

lgtm